Hi folks, as most of you might know, this Summer I got a bunch of retro hardware, including several computers.One of these computers is an AST BRAVO 486/25 with 4MB "proprietary" SIMM RAM, no other SIMMs fit those slots, so currently I cannot upgrade it at all.I "borrowed" the hardisk from my Olivetti M4 434S (since it's currently off limits, due to graphical problems), installed it in that computer and got my DR. DOS 7.03 working, most games do work, some perfectly, others laggy.I tried a lot of Apogee games, ID software (Commander Keen) and I even tried to run some Epic Megagames games.Duke Nukem 2, Monster Bash, Ken's Labyrinth, Jazz Jackrabbit, One Must Fall 2097, Doom, Doom 2 and other games don't start at all, not for the 486 DX2 (which probably is the only decent thing in that PC), but for low memory.Duke Nukem 2 require at least 2 and something MB, while I have roughly 687 kb free with the OS "just booted" and with EVERYTHING I need (Sound Blaster drivers and CD-ROM drive) loaded in high memory (LH).

So... what exactly is this computer for ? What's the maximum I can get out of 4MB of RAM, which don't even reach 4MB at all on DR. DOS 7.03 ?Ah yes, I also have Windows 3.11 installed and it works

He means it would be helpful to see what the command MEM /C displays to screen. If text goes away too fast, just add a /P parameter (/P for pause).You can also enter MEM /C >mem.txt and get a text file.

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.In what to one race is no time at all, another race can rise and fall..." - The Minstrel

I have no idea what most of the lines mean, for example the "HISTORY=ON,512,ON" in the config or the "/L:*numbers*" part before loading certain things, like KILLER or CTMOUSE (which are all "REM"med, so they don't load at all anyway).I do have it dual boot with MS-DOS 7.10, both systems work perfectly and both give me the exact same memory issues, although when I had this hardisk in the Olivetti, every game I had here worked perfectly and used all the 16MB of RAM it had !!! So why now it doesn't read these 4 megabytes ? They're all detected correctly in the computer startup, and in "mem" aswell, I only have 627K of free DOS memory, though for some reason...

Doesn't look correct to me. 1.4 MB XMS memory are missing. There are 3.4 MB of XMS from which ~2 MB are converted to EMS. But the rest is not listed as available.

I'd recommend removing EMM386 from config.sys, as most games from 199x are using XMS anyway. It's important to understand that XMS and EMS are not interchangeable. If a game needs 2 MB XMS then it's completely irrelevant how much EMS memory is available. (and vice-versa)

Doesn't look correct to me. 1.4 MB XMS memory are missing. There are 3.4 MB of XMS from which ~2 MB are converted to EMS. But the rest is not listed as available.

I'd recommend removing EMM386 from config.sys, as most games from 199x are using XMS anyway. It's important to understand that XMS and EMS are not interchangeable. If a game needs 2 MB XMS then it's completely irrelevant how much EMS memory is available. (and vice-versa)

Well... That is true... He only mentioned that he had a little over 640k avaliable.I only read the 3.xxx portion and as stupid as I am, I just asumed.Well... Need to do better in the future, stupid me. So I read that he thought that he could not get past some 640kb to 700kb Ram loaded.

Anyway...I think he will have better luck, sticking to MS-Dos-6.22. I think there are software issues on his installation.Or some of the chips on one of his modules, might be bad. I truly think the motherboard it self are perfectly fine.Yet, as I only have used Microsoft Dos and neighter DR nor IBM Dos, then I can not give any advice on his setup files.

Last edited by brostenen on 2017-12-05 @ 14:28, edited 1 time in total.

Don't eat stuff off a 15 year old never cleaned cpu cooler.Those cakes make you sick I tell.... (never tried though)

Those look like standard 72-pinn SIMMs to me. Are we sure he can only use 4MB? He might be able to bump up to 8MB or even 16MB. And yes, those contacts look corroded/dirty as all hell. Get some DeoxIt contact cleaner and a good cloth or even a paper towel and clean that stuff. You can spray DeoxIt right on the contact sockets after you remove the RAM. An old toothbrush will clean all the contacts. Let it dry and then reinstall the (cleaned) RAM.